Polycrystalline PbSe for mid-wave infrared (IR) photodetectors is an attractive material option due to its high operating/ambient temperature operation and relatively easy and cheap fabrication process, making it a candidate for low-power, small footprint, uncooled/passively cooled photodetectors. However, there are many material challenges that reduce the specific detectivity (D*) of these detectors. In this work, we demonstrate that it is possible to improve upon this metric by externally modulating the effective lifetime of conducting carriers by application of a back-gate voltage that can control the recombination rate of carriers in the detector by increasing the passivation of PbSe. We build a back-gated PbSe detector, in which we experimentally observe unambiguous signature of effective carrier modulation with a back-gate voltage for different temperatures. We develop a quantitative model for the detector that captures and closely benchmarks this modulation, which is then used to project the increase in D* in better optimized detector designs. This approach when combined with other techniques, such as plasmonic enhancement of light absorption, can lead to substantive enhancement of performance in PbSe mid-wave IR detectors widening their application space.

中文翻译：

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外在电压控制多晶PbSe中波红外光电探测器中有效载流子寿命的方法，以提高检测能力

用于中波红外（IR）光电探测器的多晶PbSe是一种有吸引力的材料选择，因为它的高工作/环境温度操作以及相对容易和便宜的制造工艺，使其成为低功耗，占地小，未冷却/被动冷却的光探测器的候选。但是，存在许多物质上的挑战，这些挑战降低了这些探测器的比探测率（D *）。在这项工作中，我们证明可以通过施加背栅电压来外部调节导电载流子的有效寿命，从而提高这一指标，该背栅电压可以通过增加PbSe的钝化来控制检测器中载流子的复合率。我们构建了背栅PbSe检测器，其中我们通过实验观察到在不同温度下使用背栅电压进行有效载波调制的明确特征。我们为检测器开发了一个定量模型，该模型可以捕获并严密标定此调制，然后将其用于预测更好优化的检测器设计中D *的增加。当与其他技术（例如光吸收的等离激元增强）结合使用时，该方法可导致PbSe中波红外探测器的性能得到实质性增强，从而扩大了其应用空间。